The Joint Force Headquarters National Capital Region will guard America's "center of gravity," said the new organization's commander, Army Maj. Gen. Galen Jackman.

The command amalgamates all Defense Department elements and the Coast Guard. The Army Military District of Washington, the Naval District of Washington, the Marine Corps National Capital Region Command and the Air Force's 11th and 89th wings are the major component commands in the new joint force. Normally, there will be between 3,000 and 4,000 personnel in the command, officials said.

The command is the latest manifestation of the trend toward jointness in the military. It was given a boost after the experiences of Sept. 11, 2001. There was no joint headquarters to coordinate military support to lead agents at the Pentagon, Jackman said. Defense Secretary Donald H. Rumsfeld ordered the creation of the command in Washington in June 2003. The command formally activated with ceremonies at Fort Myer, Va., today.

As the Joint Force Headquarters commander, Jackman will answer to Air Force Gen. Ralph E. Eberhart, the commander of U.S. Northern Command.

The new command will plan and coordinate for military assistance to homeland defense and civil support in the District of Columbia and the Maryland and Virginia suburban counties. A major portion of the command's mission is to coordinate and act as liaison with local law enforcement and first responders. The command also will work with state and federal entities, ranging from the White House Military Office to the U.S. Park Police.

Officials said the command will work with all jurisdictions to form plans in the event of attacks and will support national-level ceremonies. Jackman said that in the past year, the command has been activated six times. It participated in cleanup after Hurricane Isabel in September 2003, was involved in security and logistics for the president's State of the Union address in January, and responded to the February ricin incident on Capitol Hill. More recently, the command coordinated the World War II Memorial dedication ceremonies, the Reagan funeral and a homeland-defense exercise. "We learned from each of these," Jackman said.

The new command really is not new to the component members, both Jackman and his second-in-command, Navy Rear Adm. Jan Gaudio, said. On the ceremonial side, the various service components have had to work closely together for years. During the Reagan funeral, for example, Jackman was in charge of the ceremonies, while Gaudio was in charge of the military contributions to the logistics and security efforts.

"The nation goes to war as a joint force," Gaudio said. "It's logical to respond in the National Capital Region as a joint force."

The new command also has responsibility to sift through threat reports and respond accordingly. It will be supporting other agencies, such as the Department of Homeland Security or one of the local jurisdictions. The command, for example, will head the military assistance to the presidential inauguration in January. Planners in the command will work out contingency plans and procedures with local, state and federal authorities.

The new command will stop the ad hoc nature of past operations. In the aftermath of the plane hitting the Pentagon, the services joined to support first the Arlington Fire Department and then the FBI. Had a joint command existed, "there were forces we might have brought to bear more quickly," Jackman said.